Condensing device for overhead material of stabilizer column in benzene hydrogenation process

Abstract

The utility model discloses a kind of benzene hydrogenation process in stabilizing tower overhead material condensing device, including condenser and reflux tank, condenser is shell-and-tube heat exchanger, the upper portion of shell side shell of condenser is provided with air inlet, the bottom of the shell side shell of condenser is communicated with liquid storage tank, the bottom of liquid storage tank is communicated with reflux tank by liquid down pipe, the outer side of the shell side shell of condenser above liquid storage tank is provided with jacket, the bottom of jacket is provided with communicating pipe, the lower end of communicating pipe is inserted into the lower portion in liquid storage tank, the top of liquid storage tank is communicated with the top of jacket by gas delivery pipe, the lower portion of jacket is provided with exhaust port, and the outer wall of condenser shell side shell in jacket is provided with spiral half pipe. Above all, the utility model has the advantages of good condensing effect, stable conveying, and can improve the gas-liquid separation effect.

Description

Technical Field

[0001] This utility model relates to the technical field of condensation equipment for top materials of a stabilizer tower, specifically to a condensation device for top materials of a stabilizer tower in a benzene hydrogenation process. Background Technology

[0002] The products of benzene hydrogenation may contain small amounts of unreacted hydrogen, light hydrocarbons (such as methane and ethane), hydrogen sulfide, and other light components. The presence of these light components increases the volatility of benzene, potentially failing to meet downstream storage or transportation specifications. Furthermore, if these light components (especially hydrogen) enter subsequent benzene distillation columns or storage systems, they may pose safety hazards or increase equipment load. The stabilization column, also known as a stripping column or light component removal column, is a key piece of equipment in the subsequent distillation unit. Its function is to remove these low-boiling-point impurities from the benzene product through distillation, preventing them from affecting the purity of subsequent processes or the final product, and ensuring that the light component content of the benzene product meets standards. During operation, impurity gases and a small amount of benzene product vapor enter the top material condenser of the stabilization column for cooling. Some of the gas condenses into liquid, which enters the reflux tank. The hydrogenated oil separated in the reflux tank is returned to the stabilization column, while the uncondensed gas is sent to the subsequent exhaust gas cooler for further cooling.

[0003] Since the gas at the top of the stabilizer tower mainly consists of non-condensable gases such as C4 and C5 alkanes, H2, NH3, H2S, and H2O, the condensation effect is poor after these gases pass through the top condenser. Furthermore, the gas and liquid phases are relatively large, and the liquid phase easily disperses into fine droplets, making gravity settling separation difficult. This leads to unsatisfactory gas-liquid separation in the reflux tank and unstable tower pressure. During transport, the intermittent alternation of gas and liquid phases through the pipeline causes drastic fluctuations in flow rate and pressure. Simultaneously, the high-speed gas phase can push the liquid phase, creating a liquid hammer effect that can easily damage pipeline supports or equipment connections. Therefore, developing a condensation device for the top material of the stabilizer tower in the benzene hydrogenation process that offers good condensation, stable transport, and improved gas-liquid separation is objectively necessary. Utility Model Content

[0004] The purpose of this invention is to provide a condensation device for the top material of the stabilizer in the benzene hydrogenation process, which has good condensation effect, stable conveying, and can improve gas-liquid separation effect.

[0005] The purpose of this utility model is achieved as follows: it includes a condenser and a reflux tank. The condenser is a shell-and-tube heat exchanger. An air inlet is provided at the upper part of the shell side of the condenser. A liquid storage tank is connected to the bottom of the shell side of the condenser. The bottom of the liquid storage tank is connected to the reflux tank through a liquid outlet pipe. A jacket is provided on the outer side of the condenser shell side above the liquid storage tank. A connecting pipe is provided at the bottom of the jacket. The lower end of the connecting pipe extends into the lower part of the liquid storage tank. The top of the liquid storage tank is connected to the top of the jacket through a gas supply pipe. An exhaust port is provided at the lower part of the jacket. A spiral half-pipe is provided on the outer wall of the condenser shell side inside the jacket.

[0006] Furthermore, a demister is installed below the connection between the gas pipeline and the liquid storage tank.

[0007] Furthermore, a liquid level sensor is installed inside the storage tank, and a solenoid valve is installed on the downcomer pipe.

[0008] Furthermore, the lower end of the drain pipe extends into the bottom of the return tank.

[0009] Furthermore, the top of the reflux tank is connected to the top of the jacket via a return gas pipe, and a vacuum pump is installed on the return gas pipe.

[0010] Furthermore, a spiral plate is provided on the spiral half-tube along its length.

[0011] Furthermore, the gas pipeline is tangentially connected to the jacket.

[0012] This invention relates to the condensation of the top material in a stabilizer tower during benzene hydrogenation. During tower operation, a mixture of light component impurities and a small amount of benzene product vapor is discharged from the top of the stabilizer tower and piped into the upper shell side of the condenser. There, it exchanges heat with the condensing medium flowing into the tube side of the condenser. The condensing medium absorbs heat from the mixture through the heat exchange tubes, causing some of the mixture to condense into liquid. This liquid falls to the bottom of the condenser shell side and accumulates. Since the liquid storage tank is connected to the condenser shell side, this liquid flows into the storage tank. The liquid then passes through the lower... The liquid flows into the return tank through the liquid pipe, controlling the liquid's downward flow rate and volume to maintain a relatively stable liquid level in the storage tank. Uncondensed mixed gas is sent into the jacket through the gas delivery pipe at the top of the storage tank. At the same time, a condensing medium is introduced into the spiral half-pipe. The mixed gas flows from top to bottom in the jacket and exchanges heat with the condensing medium in the spiral half-pipe during the flow, condensing the mixed gas again. Finally, the remaining gas is discharged from the exhaust port at the bottom of the jacket and sent to the subsequent process for further processing. The condensed liquid is sent back to the storage tank through the connecting pipe. In this invention, the mixed gas discharged from the top of the stabilizer tower is fed into the condenser, first entering the shell side of the condenser, and then entering the jacket. In the shell side, heat is absorbed from the mixed gas through the heat exchange tubes, and in the jacket, heat is absorbed from the mixed gas through the spiral half-tube. At the same time, the condensing medium in the spiral half-tube can also condense the mixed gas in the shell side. Compared with existing condensers, this invention has a better condensation effect. Secondly, the condensed liquid is discharged from the bottom of the storage tank, and a layer of liquid always accumulates at the bottom of the storage tank. This layer of liquid can effectively block the gas from being discharged through the lower liquid pipe, solving the problem of the intermittent alternation of gas and liquid phases through the lower liquid pipe, thereby solving the problem of drastic fluctuations in flow and pressure. At the same time, it eliminates the liquid hammer phenomenon formed by the high-speed gas phase pushing the liquid phase. The liquid delivery is stable and is not easy to damage the pipe supports or equipment connection parts. The fine droplets in the gas phase can be further collected and condensed through the subsequent jacket, and can be effectively separated by gravity sedimentation. There is less gas phase in the reflux tank, which has little impact on the tower pressure of the stabilizer tower. In summary, this invention has the advantages of good condensation effect, stable delivery, and improved gas-liquid separation effect. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0014] In the diagram: 1-Condenser, 2-Reflux tank, 3-Air inlet, 4-Liquid storage tank, 5-Lower liquid pipe, 6-Jacket, 7-Connecting pipe, 8-Gas delivery pipe, 9-Exhaust port, 10-Spiral half-pipe, 11-Demister, 12-Level sensor, 13-Solenoid valve, 14-Return gas pipe, 15-Vacuum pump, 16-Spiral plate. Detailed Implementation

[0015] The present invention will be further described below with reference to the accompanying drawings, but this description is not intended to limit the present invention in any way. Any changes or improvements made based on the present invention shall fall within the protection scope of the present invention.

[0016] like Figure 1 As shown, this utility model includes a condenser 1 and a reflux tank 2. The reflux tank 2 is used to store the condensate condensed in the condenser 1. The condenser 1 is a shell-and-tube heat exchanger. An air inlet 3 is provided at the upper part of the shell side of the condenser 1. A liquid storage tank 4 is connected to the bottom of the shell side of the condenser 1. The bottom of the liquid storage tank 4 is connected to the reflux tank 2 through a liquid outlet pipe 5. A jacket 6 is provided on the outer side of the shell side of the condenser 1 above the liquid storage tank 4. A connecting pipe 7 is provided at the bottom of the jacket 6. The lower end of the connecting pipe 7 extends into the lower part of the liquid storage tank 4. The top of the liquid storage tank 4 is connected to the top of the jacket 6 through a gas supply pipe 8. An exhaust port 9 is provided at the lower part of the jacket 6. A spiral half-pipe 10 is provided on the outer wall of the shell side of the condenser 1 inside the jacket 6. The open side of the spiral half-pipe 10 is welded and sealed to the outer wall of the shell side of the condenser 1. A condensing medium is introduced into the spiral half-pipe 10, which can simultaneously condense the mixed gas on both sides of the shell side.

[0017] This invention relates to the condensation of the top material in a stabilizer tower during benzene hydrogenation. During tower operation, a mixture of light component impurities and a small amount of benzene product vapor is discharged from the top of the stabilizer tower and fed into the upper shell side of condenser 1 via a pipeline. There, it exchanges heat with the condensing medium flowing into the tube side of condenser 1. The condensing medium absorbs heat from the mixture through the heat exchange tubes, causing some of the mixture to condense into liquid, which falls to the bottom of the shell side of condenser 1 and accumulates. Since the liquid storage tank 4 is connected to the shell side of condenser 1, this liquid flows into the liquid storage tank 4. The liquid then flows into the lower liquid pipe 5. The return tank 2 controls the downward flow rate and volume of the liquid to maintain a relatively stable liquid level in the storage tank 4. The uncondensed mixed gas is sent into the jacket 6 from the gas delivery pipe 8 at the top of the storage tank 4. At the same time, a condensing medium is introduced into the spiral half-pipe 10. The mixed gas flows from top to bottom in the jacket 6 and exchanges heat with the condensing medium in the spiral half-pipe 10 during the flow, condensing the mixed gas again. Finally, the remaining gas is discharged from the exhaust port 9 at the bottom of the jacket 6 and sent to the subsequent process for further processing. The condensed liquid is sent back to the storage tank 4 through the connecting pipe 7.

[0018] In this invention, the mixed gas discharged from the top of the stabilizer tower is fed into the condenser 1, first entering the shell side of the condenser 1, and then entering the jacket 6. While in the shell side, heat is absorbed from the mixed gas through the heat exchange tubes. While in the jacket 6, heat is absorbed from the mixed gas through the spiral half-tube 10. Simultaneously, the condensing medium in the spiral half-tube 10 can also condense the mixed gas in the shell side. Compared to existing condensers 1, this invention has a better condensation effect. Furthermore, the condensed liquid in this invention is discharged from the bottom of the storage tank 4. A layer of liquid always accumulates at the bottom, which effectively prevents gas from being discharged through the lower liquid pipe 5. This solves the problem of intermittent alternation between the gas and liquid phases passing through the lower liquid pipe, thereby solving the problem of drastic fluctuations in flow and pressure. At the same time, it eliminates the liquid hammer phenomenon caused by the high-speed gas phase pushing the liquid phase. The liquid delivery is stable and is less likely to damage the pipe supports or equipment connections. The fine droplets in the gas phase can be further accumulated and condensed through the subsequent jacket 6, and can be effectively separated by gravity settling. The amount of gas in the reflux tank 2 is small and will not affect the tower pressure of the stabilizer.

[0019] A demister 11 is installed below the connection between the gas pipeline 8 and the liquid storage tank 4. The demister 11 is an existing structure used to remove moisture from the gas. This utility model uses the demister 11 to remove the liquid entrained in the mixed gas, thereby improving the gas-liquid separation efficiency. Moreover, the mixed gas with the moisture removed will have a higher condensation efficiency after entering the jacket 6.

[0020] A liquid level sensor 12 is installed inside the liquid storage tank 4, and a solenoid valve 13 is installed on the lower liquid pipe 5. When this utility model is in operation, a certain amount of condensate needs to be kept at the bottom of the liquid storage tank 4 at all times to prevent the mixed gas containing liquid droplets from entering the return tank 2 from the lower liquid pipe 5. This requires ensuring that the condensate condensing rate of the condenser 1 is equal to the discharge rate from the lower liquid pipe 5. To achieve this, the liquid level sensor 12 monitors the liquid level in the liquid storage tank 4 and keeps the liquid level stable. When the liquid level drops, it indicates that the discharge rate of the condensate is greater than the generation rate of the condensate. At this time, the solenoid valve 13 can be controlled to reduce the discharge rate of the condensate in the lower liquid pipe 5. Conversely, when the liquid level rises, it indicates that the discharge rate of the condensate is less than the generation rate of the condensate. At this time, the solenoid valve 13 can be controlled to increase the discharge rate of the condensate in the lower liquid pipe 5.

[0021] The lower end of the drain pipe 5 extends into the bottom of the return tank 2. If the lower end of the drain pipe 5 is located at the top of the return tank 2, the condensate falling into the return tank 2 will impact the condensate in the return tank 2, thereby generating more bubbles in the condensate. However, if the lower end of the drain pipe 5 extends into the bottom of the return tank 2, the impact of the condensate can be greatly reduced, thereby reducing the generation of bubbles.

[0022] The top of the reflux tank 2 is connected to the top of the jacket 6 via a return gas pipe 14. A vacuum pump 15 is installed on the return gas pipe 14. In actual use, it was found that the condensate contains a certain amount of air bubbles. These air bubbles escape from the condensate tank 2 after entering the reflux tank 2 with the condensate. The return gas pipe 14 is installed to discharge this part of the gas. The gas enters the jacket 6 through the return gas pipe 14 for condensation again, which improves the condensation effect of the mixed gas and reduces the load on the subsequent exhaust condensation device. The vacuum pump 15 can create a negative pressure in the reflux tank 2, which improves the efficiency of gas escaping from the condensate.

[0023] A spiral plate 16 is provided on the spiral half-pipe 10 along its length direction. The spiral plate 16 is fixed on the spiral half-pipe 10, dividing the internal space of the jacket 6 into a spiral channel. The mixed gas flows in the spiral channel, eliminating the dead zone of the mixed gas flow in the jacket 6 and improving the condensation effect of the mixed gas. Secondly, the spiral half-pipe 10 has a certain thermal conductivity and can be made of materials with good thermal conductivity, increasing the heat exchange area between the mixed gas and the condensing medium, thereby improving the heat exchange efficiency of the mixed gas.

[0024] The gas supply pipe 8 is tangentially connected to the jacket 6. When the mixed gas enters the jacket 6 through the gas supply pipe 8, it will form a swirling flow in the annular jacket 6, which can increase the residence time of the mixed gas in the jacket 6 and thus improve the condensation effect of the mixed gas.

Claims

1. A condensation device for the top material of a stabilizer column in a benzene hydrogenation process, comprising a condenser (1) and a reflux tank (2), characterized in that: The condenser (1) is a shell-and-tube heat exchanger. An air inlet (3) is provided on the upper part of the shell side of the condenser (1). A liquid storage tank (4) is connected to the bottom of the shell side of the condenser (1). The bottom of the liquid storage tank (4) is connected to the return tank (2) through a liquid drain pipe (5). A jacket (6) is provided on the outer side of the shell side of the condenser (1) above the liquid storage tank (4). A connecting pipe (7) is provided at the bottom of the jacket (6). The lower end of the connecting pipe (7) extends into the lower part of the liquid storage tank (4). The top of the liquid storage tank (4) is connected to the top of the jacket (6) through a gas supply pipe (8). An exhaust port (9) is provided at the lower part of the jacket (6). A spiral half-pipe (10) is provided on the outer wall of the shell side of the condenser (1) inside the jacket (6).

2. The condensation device for the top material of the stabilizer column in a benzene hydrogenation process according to claim 1, characterized in that: A demister (11) is provided below the connection between the gas pipeline (8) and the liquid storage tank (4).

3. The condensation device for the top material of the stabilizer column in a benzene hydrogenation process according to claim 1, characterized in that: A liquid level sensor (12) is installed inside the liquid storage tank (4), and a solenoid valve (13) is installed on the liquid outlet pipe (5).

4. The condensation device for the top material of the stabilizer column in a benzene hydrogenation process according to claim 1, characterized in that: The lower end of the liquid drain pipe (5) extends into the bottom of the return tank (2).

5. The condensation device for the top material of the stabilizer column in a benzene hydrogenation process according to claim 1, characterized in that: The top of the reflux tank (2) is connected to the top of the jacket (6) through the return gas pipe (14), and a vacuum pump (15) is installed on the return gas pipe (14).

6. The condensation device for the top material of the stabilizer column in a benzene hydrogenation process according to claim 1, characterized in that: A spiral plate (16) is provided on the spiral half-tube (10) along its length direction.

7. The condensation device for the top material of the stabilizer column in a benzene hydrogenation process according to claim 1, characterized in that: The gas supply pipe (8) is tangentially connected to the jacket (6).

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